Whole genome screening for deleterious alleles in Hanwoo cattle

Abstract

Selective breeding of cattle increases the level of inbreeding and, as a result, the risk of transmitting deleterious recessive alleles in a population. Numerous genetic disorders have been identified in various breeds of cattle. Although these disorders occur sporadically, the widespread use of semen from carrier sires can increase their prevalence in a population. In this regard, routine testing and elimination of carrier bulls is essential. The availability of a large amount of genomic data enables the screening and identification of causal alleles in the absence of phenotypes. This study aimed to investigate the presence of candidate variants of genetic disorders in Hanwoo cattle using whole genome data. 16,970 cattle were genotyped using the 50K Illumina Bovine chip and imputed to the whole genome sequence level using reference data from 203 bulls. Genetic coordinates of previously reported mutations in cattle were obtained from the OMIA online database. The information was then used to screen for harmful alleles in Hanwoo cattle. Fortunately, we did not identify any candidate variants in the tested population. However, this study was limited to a small sample. Moreover, the reliability of the results could have been affected by low imputation accuracy and genotype liftover errors. In this regard, we recommend regular screening of the breeding cattle to minimize the prevalence of genetic disorders in Hanwoo cattle.